Generally, an operator gets in construction machinery, such as a hydraulic excavator or crane, and remote-controls various actuators by a pilot-type hydraulic operated valve (pilot valve) to perform various operations. Various actuators and operating machines included in the construction machinery are large in size and heavy in weight. If the operator drastically operates the actuators and operating machines, the actuators and operating machines move in a big way. This may cause, for example, large oscillations and vibrations of a carbody, and the actuators and operating machines may not be able to perform normal operations. In addition, the oscillations and vibrations of the carbody when, for example, the construction machinery is running or operating cause the oscillations and vibrations of the operating portion via hands or feet of the operator or by the inertial force of the operating portion itself.
If the oscillations and vibrations which are not intended by the operator are applied to the operating portion as above, the hydraulic operated valve is operated by the oscillations and vibrations, and the hydraulic operated valve causes the actuators to perform operations which are not intended by the operator. As a result, the oscillations and vibrations of the construction machinery may be increased. Then, the increased oscillations and vibrations of the construction machinery may increase the oscillations and vibrations of the operating portion, that is, a vicious cycle may be caused.
Therefore, for example, in both cases where the operator tilts the operating portion of the hydraulic operated valve from a neutral position and the operator returns the operating portion from the tilted position to the neutral position, it is necessary to reduce as much as possible the oscillations and vibrations of the operating portion, the oscillations and vibrations being caused by the oscillations and vibrations of the construction machinery. Therefore, operating devices including damper portions have been proposed.
FIG. 12 is a cross-sectional view showing one example of a conventional operating device (see PTL 1, for example). According to an operating device 100, when the operator operates the operating portion, such as a pedal or a lever, to tilt a tilt member 101 in a tilt direction A1, a push rod 102 is pressed downward to move downward. When the push rod 102 moves downward, a spool 107 is pressed downward via a pressing spring 106 to move downward. At this time, when an oil passage 107a extending in a direction perpendicular to an axis communicates with a pump port 108p located lower than a tank port 108t, the tank port 108t is closed by the spool 107, and the pump port 108p and an output port 108o communicate with each other. With this, the actuator of the construction machinery can be moved in a predetermined direction.
At this time, operating oil in a damper chamber 104 moves from a lower chamber 104b to an upper chamber 104a through a restrictor 105a of a damper portion 105. Therefore, a damping effect (resistance force) with respect to the operation of the operating portion (tilt member 101) can be obtained. On this account, even if the oscillations and vibrations which are not intended by the operator occur on the construction machinery, in which the operator has gotten, when the operator has operated the operating portion, the operation mistake of the operating portion by the operator due to the oscillations and vibrations can be suppressed by the resistance force, and the increase in the oscillations and vibrations of the construction machinery can be reduced.